/*
 *	FIPS-180-1 compliant SHA-1 implementation
 *
 *  Based on TropicSSL: Copyright (C) 2017 Shanghai Real-Thread Technology Co., Ltd
 * 
 *	Based on XySSL: Copyright (C) 2006-2008	 Christophe Devine
 *
 *	Copyright (C) 2009	Paul Bakker <polarssl_maintainer at polarssl dot org>
 *
 *	All rights reserved.
 *
 *	Redistribution and use in source and binary forms, with or without
 *	modification, are permitted provided that the following conditions
 *	are met:
 *
 *	  * Redistributions of source code must retain the above copyright
 *		notice, this list of conditions and the following disclaimer.
 *	  * Redistributions in binary form must reproduce the above copyright
 *		notice, this list of conditions and the following disclaimer in the
 *		documentation and/or other materials provided with the distribution.
 *	  * Neither the names of PolarSSL or XySSL nor the names of its contributors
 *		may be used to endorse or promote products derived from this software
 *		without specific prior written permission.
 *
 *	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *	"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *	LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *	FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *	OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *	SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 *	TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 *	PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *	LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *	NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *	SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/*
 *	The SHA-1 standard was published by NIST in 1993.
 *
 *	http://www.itl.nist.gov/fipspubs/fip180-1.htm
 */

#include "tinycrypt_config.h"

#if defined(TINY_CRYPT_SHA1)

#include "tinycrypt.h"

#include <string.h>
#include <stdio.h>

/*
 * 32-bit integer manipulation macros (big endian)
 */
#ifndef GET_ULONG_BE
#define GET_ULONG_BE(n,b,i)								\
	{													\
		(n) = ( (unsigned long) (b)[(i)	   ] << 24 )	\
			| ( (unsigned long) (b)[(i) + 1] << 16 )	\
			| ( (unsigned long) (b)[(i) + 2] <<	 8 )	\
			| ( (unsigned long) (b)[(i) + 3]	   );	\
	}
#endif

#ifndef PUT_ULONG_BE
#define PUT_ULONG_BE(n,b,i)								\
	{													\
		(b)[(i)	   ] = (unsigned char) ( (n) >> 24 );	\
		(b)[(i) + 1] = (unsigned char) ( (n) >> 16 );	\
		(b)[(i) + 2] = (unsigned char) ( (n) >>	 8 );	\
		(b)[(i) + 3] = (unsigned char) ( (n)	   );	\
	}
#endif

/*
 * SHA-1 context setup
 */
void tiny_sha1_starts(tiny_sha1_context * ctx)
{
	ctx->total[0] = 0;
	ctx->total[1] = 0;

	ctx->state[0] = 0x67452301;
	ctx->state[1] = 0xEFCDAB89;
	ctx->state[2] = 0x98BADCFE;
	ctx->state[3] = 0x10325476;
	ctx->state[4] = 0xC3D2E1F0;
}

static void sha1_process(tiny_sha1_context * ctx, unsigned char data[64])
{
	unsigned long temp, W[16], A, B, C, D, E;

	GET_ULONG_BE(W[0], data, 0);
	GET_ULONG_BE(W[1], data, 4);
	GET_ULONG_BE(W[2], data, 8);
	GET_ULONG_BE(W[3], data, 12);
	GET_ULONG_BE(W[4], data, 16);
	GET_ULONG_BE(W[5], data, 20);
	GET_ULONG_BE(W[6], data, 24);
	GET_ULONG_BE(W[7], data, 28);
	GET_ULONG_BE(W[8], data, 32);
	GET_ULONG_BE(W[9], data, 36);
	GET_ULONG_BE(W[10], data, 40);
	GET_ULONG_BE(W[11], data, 44);
	GET_ULONG_BE(W[12], data, 48);
	GET_ULONG_BE(W[13], data, 52);
	GET_ULONG_BE(W[14], data, 56);
	GET_ULONG_BE(W[15], data, 60);

#define S(x,n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))

#define R(t)											\
	(													\
		temp = W[(t -  3) & 0x0F] ^ W[(t - 8) & 0x0F] ^	\
		W[(t - 14) & 0x0F] ^ W[ t	   & 0x0F],			\
		( W[t & 0x0F] = S(temp,1) )						\
		)

#define P(a,b,c,d,e,x)									\
	{													\
		e += S(a,5) + F(b,c,d) + K + x; b = S(b,30);	\
	}

	A = ctx->state[0];
	B = ctx->state[1];
	C = ctx->state[2];
	D = ctx->state[3];
	E = ctx->state[4];

#define F(x,y,z) (z ^ (x & (y ^ z)))
#define K 0x5A827999

	P(A, B, C, D, E, W[0]);
	P(E, A, B, C, D, W[1]);
	P(D, E, A, B, C, W[2]);
	P(C, D, E, A, B, W[3]);
	P(B, C, D, E, A, W[4]);
	P(A, B, C, D, E, W[5]);
	P(E, A, B, C, D, W[6]);
	P(D, E, A, B, C, W[7]);
	P(C, D, E, A, B, W[8]);
	P(B, C, D, E, A, W[9]);
	P(A, B, C, D, E, W[10]);
	P(E, A, B, C, D, W[11]);
	P(D, E, A, B, C, W[12]);
	P(C, D, E, A, B, W[13]);
	P(B, C, D, E, A, W[14]);
	P(A, B, C, D, E, W[15]);
	P(E, A, B, C, D, R(16));
	P(D, E, A, B, C, R(17));
	P(C, D, E, A, B, R(18));
	P(B, C, D, E, A, R(19));

#undef K
#undef F

#define F(x,y,z) (x ^ y ^ z)
#define K 0x6ED9EBA1

	P(A, B, C, D, E, R(20));
	P(E, A, B, C, D, R(21));
	P(D, E, A, B, C, R(22));
	P(C, D, E, A, B, R(23));
	P(B, C, D, E, A, R(24));
	P(A, B, C, D, E, R(25));
	P(E, A, B, C, D, R(26));
	P(D, E, A, B, C, R(27));
	P(C, D, E, A, B, R(28));
	P(B, C, D, E, A, R(29));
	P(A, B, C, D, E, R(30));
	P(E, A, B, C, D, R(31));
	P(D, E, A, B, C, R(32));
	P(C, D, E, A, B, R(33));
	P(B, C, D, E, A, R(34));
	P(A, B, C, D, E, R(35));
	P(E, A, B, C, D, R(36));
	P(D, E, A, B, C, R(37));
	P(C, D, E, A, B, R(38));
	P(B, C, D, E, A, R(39));

#undef K
#undef F

#define F(x,y,z) ((x & y) | (z & (x | y)))
#define K 0x8F1BBCDC

	P(A, B, C, D, E, R(40));
	P(E, A, B, C, D, R(41));
	P(D, E, A, B, C, R(42));
	P(C, D, E, A, B, R(43));
	P(B, C, D, E, A, R(44));
	P(A, B, C, D, E, R(45));
	P(E, A, B, C, D, R(46));
	P(D, E, A, B, C, R(47));
	P(C, D, E, A, B, R(48));
	P(B, C, D, E, A, R(49));
	P(A, B, C, D, E, R(50));
	P(E, A, B, C, D, R(51));
	P(D, E, A, B, C, R(52));
	P(C, D, E, A, B, R(53));
	P(B, C, D, E, A, R(54));
	P(A, B, C, D, E, R(55));
	P(E, A, B, C, D, R(56));
	P(D, E, A, B, C, R(57));
	P(C, D, E, A, B, R(58));
	P(B, C, D, E, A, R(59));

#undef K
#undef F

#define F(x,y,z) (x ^ y ^ z)
#define K 0xCA62C1D6

	P(A, B, C, D, E, R(60));
	P(E, A, B, C, D, R(61));
	P(D, E, A, B, C, R(62));
	P(C, D, E, A, B, R(63));
	P(B, C, D, E, A, R(64));
	P(A, B, C, D, E, R(65));
	P(E, A, B, C, D, R(66));
	P(D, E, A, B, C, R(67));
	P(C, D, E, A, B, R(68));
	P(B, C, D, E, A, R(69));
	P(A, B, C, D, E, R(70));
	P(E, A, B, C, D, R(71));
	P(D, E, A, B, C, R(72));
	P(C, D, E, A, B, R(73));
	P(B, C, D, E, A, R(74));
	P(A, B, C, D, E, R(75));
	P(E, A, B, C, D, R(76));
	P(D, E, A, B, C, R(77));
	P(C, D, E, A, B, R(78));
	P(B, C, D, E, A, R(79));

#undef K
#undef F

	ctx->state[0] += A;
	ctx->state[1] += B;
	ctx->state[2] += C;
	ctx->state[3] += D;
	ctx->state[4] += E;
}

/*
 * SHA-1 process buffer
 */
void tiny_sha1_update(tiny_sha1_context * ctx, unsigned char *input, int ilen)
{
	int fill;
	unsigned long left;

	if (ilen <= 0)
		return;

	left = ctx->total[0] & 0x3F;
	fill = 64 - left;

	ctx->total[0] += ilen;
	ctx->total[0] &= 0xFFFFFFFF;

	if (ctx->total[0] < (unsigned long)ilen)
		ctx->total[1]++;

	if (left && ilen >= fill) {
		memcpy((void *)(ctx->buffer + left), (void *)input, fill);
		sha1_process(ctx, ctx->buffer);
		input += fill;
		ilen -= fill;
		left = 0;
	}

	while (ilen >= 64) {
		sha1_process(ctx, input);
		input += 64;
		ilen -= 64;
	}

	if (ilen > 0) {
		memcpy((void *)(ctx->buffer + left), (void *)input, ilen);
	}
}

static const unsigned char sha1_padding[64] = {
	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/*
 * SHA-1 final digest
 */
void tiny_sha1_finish(tiny_sha1_context * ctx, unsigned char output[20])
{
	unsigned long last, padn;
	unsigned long high, low;
	unsigned char msglen[8];

	high = (ctx->total[0] >> 29)
	    | (ctx->total[1] << 3);
	low = (ctx->total[0] << 3);

	PUT_ULONG_BE(high, msglen, 0);
	PUT_ULONG_BE(low, msglen, 4);

	last = ctx->total[0] & 0x3F;
	padn = (last < 56) ? (56 - last) : (120 - last);

	tiny_sha1_update(ctx, (unsigned char *)sha1_padding, padn);
	tiny_sha1_update(ctx, msglen, 8);

	PUT_ULONG_BE(ctx->state[0], output, 0);
	PUT_ULONG_BE(ctx->state[1], output, 4);
	PUT_ULONG_BE(ctx->state[2], output, 8);
	PUT_ULONG_BE(ctx->state[3], output, 12);
	PUT_ULONG_BE(ctx->state[4], output, 16);
}

/*
 * output = SHA-1( input buffer )
 */
void tiny_sha1(unsigned char *input, int ilen, unsigned char output[20])
{
	tiny_sha1_context ctx;

	tiny_sha1_starts(&ctx);
	tiny_sha1_update(&ctx, input, ilen);
	tiny_sha1_finish(&ctx, output);

	memset(&ctx, 0, sizeof(tiny_sha1_context));
}

/*
 * SHA-1 HMAC context setup
 */
void tiny_sha1_hmac_starts(tiny_sha1_context * ctx, unsigned char *key, int keylen)
{
	int i;
	unsigned char sum[20];

	if (keylen > 64) {
		tiny_sha1(key, keylen, sum);
		keylen = 20;
		key = sum;
	}

	memset(ctx->ipad, 0x36, 64);
	memset(ctx->opad, 0x5C, 64);

	for (i = 0; i < keylen; i++) {
		ctx->ipad[i] = (unsigned char)(ctx->ipad[i] ^ key[i]);
		ctx->opad[i] = (unsigned char)(ctx->opad[i] ^ key[i]);
	}

	tiny_sha1_starts(ctx);
	tiny_sha1_update(ctx, ctx->ipad, 64);

	memset(sum, 0, sizeof(sum));
}

/*
 * SHA-1 HMAC process buffer
 */
void tiny_sha1_hmac_update(tiny_sha1_context * ctx, unsigned char *input, int ilen)
{
	tiny_sha1_update(ctx, input, ilen);
}

/*
 * SHA-1 HMAC final digest
 */
void tiny_sha1_hmac_finish(tiny_sha1_context * ctx, unsigned char output[20])
{
	unsigned char tmpbuf[20];

	tiny_sha1_finish(ctx, tmpbuf);
	tiny_sha1_starts(ctx);
	tiny_sha1_update(ctx, ctx->opad, 64);
	tiny_sha1_update(ctx, tmpbuf, 20);
	tiny_sha1_finish(ctx, output);

	memset(tmpbuf, 0, sizeof(tmpbuf));
}

/*
 * output = HMAC-SHA-1( hmac key, input buffer )
 */
void tiny_sha1_hmac(unsigned char *key, int keylen,
	       unsigned char *input, int ilen, unsigned char output[20])
{
	tiny_sha1_context ctx;

	tiny_sha1_hmac_starts(&ctx, key, keylen);
	tiny_sha1_hmac_update(&ctx, input, ilen);
	tiny_sha1_hmac_finish(&ctx, output);

	memset(&ctx, 0, sizeof(tiny_sha1_context));
}

#endif
